Peter Breck and Russell Johnson starred together in the western series, Black Saddle.
This is the final episode that Linda Evans appears on in the third season.
Series regular Richard Long (who would later star in the sitcom Nanny and the Professor (1970)) and guest star Russell Johnson (of Gilligan's Island (1964)) both played a character on each of those shows named "The Professor." They had previously also been co-stars in the service comedy film Back at the Front (1952).